Rotary pump



Aug. 22, 1933. M. E. zlMMr-:RER

ROTARY PUMP Filed Sept. 11 1930 2 Sheets-Sheet 1 YVQJ-z/Ef" 77260@ E.Zimmerer? AU8 22, 1933 4M. E. ZIMMERER 1,923,291

ROTARY PUMP Filed Sept'. 1l, 1930 Sheets-Sheet 2 1) N 53@ Si? m nVEL-#CUF Zark Ef Zimmerer Patented Aug. 22, i933 UNITED STATES PARENTOFFICE Kingston Products Corporation, Kokbknp a Corporation of IndianaApplication September l1, 1930 Serial N0. 481,098

1 claim. (ci. 10s-132i This invention relates to an improved rotary pumphaving particular utility in pumping volatile fluids such as gasolineand more particularly to such a device having a plurality of independentpump compartments.

The various forms of rotary pumps for pumping volatile fluids such asgasoline, do not possess a very high efficiency due to the relativelyhigh amount of electrical energy consumed in their operation for a givenvolume of fluid delivered. In addition, these pumps employ for the mostpart contacting moving parts which are subjected to wear, necessitatingreplacement and hence decreasing the operative life of the pump.

Further when such pumps are constructed with a plurality of independentchambers, it is the custom to form the same in three pieces withpartitions integral with the casing separating the various pumpcompartments. This form of construcy tion necessitates an expensive andtedious metal working operation and moreover because of 'the` number ofparts required results in a rather expensive pump. y

In addition due to the volatility and inflammability of gasoline, it isnecessary to provide a. liquid type packing for the pump bearing inwhich the shaft extension connected to the power source is journalled.The usual packingvglands employed frictionally grip the shafts with suchtenacity that a material loss of power is experienced in overcoming thisfrictional force.

I have now provided a rotaryp p havingra plurality of independent pumpchambers which overcomes to a great extent the objectionable featurespointed out in connection with known forms of rotary pumps.

It is accordingly an object of this invetion to provide a rotary twopiece\pump .having a plurality of pump compartments.

It is a further object of thisinvention to provide a. multi-chamberrotary punp-which is compact and simple in construction, has a smallinitial cost and a materially greater operating efficiency than knownpumps. A

A further important object of this invention is to provide a packinggland for the extended end of the pump shaft which provides an effectiveliquid seal and at the same time exerts a materially 'smaller frictionalgrip on the shaft than known forms of packing glands.

It is a further important object of this invention to provide animproved lubricating and cooling system for the extended shaft bearing.

Other and lfurther important objects of this \1 4 formed on said plate7.

invention will become apparent from the following descriptinand appendedclaim.

Rcferrin'gnow t0 the drawings:

Figure 1 is a vertical sectibnal liew through my improved pump."`4 f Y.

Figure 2\isa section inline II-II of Figure 1.

Figure 3 shows a modified form of rotary pivot for the pu` p rotors-1Figure 4 iscloses another modified form of such pivot.

Onthe drawings; 71.?

The pump indicatedjny the reference numeral 1 comprises a housingarcasing 2 having a section 3 with a-smooth bore 4 therein for receivingthe pumpxotors 5. and a plate 'I secured by 70 screws 8 to the section 3to form a rear closure for the pump b ore 4.

The frontgface 9 of said section 3 is formed with an integral hollowextension 10 providing a bearing 11 for the pump shaft 12. The oppo- 75site end 13 of said shaft 12 is journalled in a hub Preferably, anantifriction bushing 15 is located between the walls of saiiefhub 14 andthe end of said shaft.

That part of the pump shaft 12 located in the 30 bore 4 is formed, inthe structure shown, with a pair of abutting cams 16 having their peakpoints 18 spaced 180 apart about the shaft. Preferably the cams 16 areforged integrally with the shaft 12 but if desired may be madeseparately 85 and secured to the shaft by keys or pins.

The bore 4 in the pump section 3 is divided into two equal independentpump compartments 19 and 20 by a partition plate 21 located in the pumpat the point where the cams 16 abut. 90 Said plate 21 has an aperture 22therein of suicient diameter to permit the partition to be readilyslipped over said cams i6. The diameter of said partition is slightlyless than that of the pump bore 4 but if desired it"may be made with 95such a diameter as to provide apress fit with the walls of said bore. Inthe first however, the amount of leakage occasioned by the very smallclearance between the periphery of said partition and the walls of saidbore is so small as to fail to overcome the advantages resuming from theuse of the floating partition and accord .lngly this form is to bepreferred.

The pump rotors 5 are eccentricaliy mounted 105 in each pump compartment19 and 20, by means of conventional ball bearings 24 which rather snuglyfit over the cams 16. Said ball bearings comprise inner and outer ballraces 25 which house the balls 26. The lands 27 of said races 110 are,as shown, of less width than the width of cams 16 which the racesencircle.

Each pump rotor 5 has an inner diameter permitting it to be readilyslipped over the outer ball races and an outer diameter such that theportion of the rotor periphery in line with the peak of the cam on whichit is mounted just clears the Wall of the pump compartment. From thispoint the space between the rotor periphery of each rotor and the wallof the pump compartment gradually increases in size to a point spacedapart 180 and gradually decreases in size from said latter point back tosaid first point. There is thus no rubbing action between the pumprotors and the walls of the pump chambers and hence no wear of theseparts. There is moreover, no fluid leakage through this clearance aswill be later explained. I have found that a 1000 of an inch at theabove mentioned point produces very good results.

Each rotor 5 is operatively associated with its pump compartment bymeans of a rotary pivot 28 which permits a rolling or wiping action of arotor about the walls of the compartment when the pump shaft 12 isrotated, but prevents rotation of the rotor with said shaft. Said pivots28 are formed by carefully drilling a cylindrical longitudinallyextending opening 29 through the upper wall of the pump section 3 to adepth equal to the depth of the bore 4. Said opening 29 at its undersideintersects said bore 4 to provide a narrow communicating passage 29atherebetween. A pair of rotary pivot blocks 30, one for each pump rotor5, having a cross section like that of opening 29 is then located insaid opening 29. Said blocks 30 are spaced from each other to provide aspace for the reception in said opening 29 of a tongue 31 on thepartition 21 to prevent rotative movement of said partition. Each ofsaid blocks 30 is provided with a slot 32 opening toward the pump bore 4through said passage 29a. A radial pivot blade 33 is secured to eachpump rotor 5 and extends through the passage 29a into the slot 32 ineach pivot block 30, wherein it reciprocates as the rotor to which it isfixed wipes around the wall of a pump compartment. The slight tiltingaction 'necessary in the pivot 28 to permit the wiping or rolling actionof the pump rotor is provided by rotation of the pivot block 30 in theopening 29.

Each pivot blade 33 is xedly secured to a pump rotor by forming thelower end of the blade with a headed portion 34 which is located in arecess 35 in the rotor. The metal about said slot is then worked tofirmly anchor said base 34 in place. This joint is stronger than awelded or soldered joint and accordingly increases the durability of thepump.

The rotary pivots 28 may take other forms than that shown in Figures 1and 2. For example, in

rotor having a clearance of approximately vFigure 3 such a pivot isformed by a U-shaped slot 36 opening into the bore 4 and a pivot blade37 having a chamfered head 38 received in said slot. Said blade 37reciprocates in said slot as the rotor operates and due to the formationof the head 38 has a slight tilting action therein.

In Figure 4 I have shown another form of pivot comprising a member 39having a plane base 40 and a curved outer surface 41. The upper portionof said outer surface is secured as at 42 in a groove 43 in the upperwall of the pump casing and reciprocates in a rectangular slot 44 in therotor 5.

The blades 33, Figures 1 and 2, not only act as pivots for the rotors 5but also divide the pump chambers 19 and 20 into a suction side 45 andpressure side 46. The suction side 45 of each pump compartment has aninlet port 47 leading thereinto while the pressure side is incommunication with an outlet port 48.

Pumps of this nature when used in gasoline stations are operated by anelectric motor controlled by the delivery nozzle from the gasoline tank.The release of the delivery nozzle from the tank starts the motor andpump so that in many instances the pump is in operation before thenozzle is opened to deliver the gasoline therefrom. To take care of thefluid pumped into the outlet port in such cases, a relief port 49 isprovided between the outlet port 48' and inlet port 47. Said relief port49 is controlled, adjacent its connection with the inlet port 47 by avalve 50 having a head 50a seating against the end 51 of said reliefport. Said valve 50 has a stem 52 operable in a sleeve 53 secured inplace by a member 55 threaded in the bore 56. The valve is normallyretained against vits seat by a compression spring 57 bearing againstthe valve head and member 55 and regulated to yield at a predeterminedpressure to permit the valve to unseat and open said relief port. Apacking gasket 58 secured in place by a nut 59, threaded to the end ofmember 55 prevents leakage of fluid through said bore 56.

Leakage of fluid through the shaft journal 10 is prevented by means of apacking' gland 60 located in a recess 6l in the outer end of saidjournal. Said packing gland 60 comprises a hollow resilient cylinder 61apreferably of cork fitting about said shaft 12 and having a groove 62about the periphery thereof. The ends 63 of said cork cylinder 61a areinwardly inclined and abut against metal rings 64 and 65 which haveinclined faces 66 corresponding to the inclination of said ends 63. Theinner ring 64 fits against the outer end of the bearing 11 while theouter ring 65 is acted on by a compression spring 69a which bears at itsother end against an adjustable cap 67 threaded to the end of saidjournal 10. Said cap has an aperture 68 therein for the reception of asleeve 69 which surrounds the shaft 12 and is received at its inner endin a groove in the ring 65. Said sleeve 69 collects fluid which leakspast the packing gland 60.

In this type of gland, the spring 69a maintains a constant pressureagainst the cork cylinder 61a thereby compressing the same and forcingthe material of the packing 60 into tight engagement with the shaft 12.The groove 62 permits greater compression about the periphery of thegland 60 to thereby distort the gland so that the axial pressure causedby threading the cap 67 on the journal 10 exerts a greater radialpressure upon the shaft 12 than would be the case if the gland 60 werenot provided with a groove. This gripping engagement does not, as willbe readily appreciated, set up a force in opposition to the rotation ofthe shaft in any degree comparable with that set up with known forms ofpacking glands.

In this pump I utilize the action of the pump and the fluid operated onby the pump to cool and lubricate the bearing ll. For this purpose acircular groove 70 is provided in the face of the ring 64 seatingagainst the end of the bearing l1 which communicates with a passage 71leading through the wall of the journal 10 into the suction side of theadjacent pump compartment. Preferably a small metering pin (not shown)is located in the outlet 72 from said passage '11, to regulate the flowof fluid through said passage. As will be apparent the suction of thepump acting through the passage l1 causes fluid to flow from the suctionside of the pump compartment adjacent the bearing 11 along the shaft 12into the groove 'l0 and back to the pump compartment through the passage'71 thereby effectively cooling and lubricating the pump bearing 11.

The width of the rotors 5 is such as to provide a snug butnon-contacting nt with the sides of the pump compartments 19 and 20 tothereby prevent' leakage past said side surfaces. The thickness of therotor walls may of course be varied but for best results they are madeas thin as possible consistent with sufficient strength to provideanchorage for the pivot blades 33`- The thinner the walls are made theless will be thel centrifugal force acting on the pump shaft.

The small clearance provided at all times between the periphery oi' therotors 5 and walls of the pump compartment is sealed by the fluid pumpedand hence substantially no leakage takes place from the suction side ofthe pump compartments to the pressure side thereof. What little leakagedoes occur is more than offset by the nonwearing structure provided.

I have found that with a pump of this construction, the electricalenergy necessary to drive a pump of a given capacity is about 50% lessthan that required for known pumps of similar capacity. For example,with a pump of the size ordinarily employed at gasoline stations I canpump 15 gallons of gasoline per minute under 18 pounds pressure with aV3 H. P. motor.

While I have disclosed a pump having but two pump compartments it willbe understood that as many may be provided as desired, by merely settingolf the spaces to be occupied as pump compartments by the floatingpartitions disclosed, In this way the number of parts of the pump is notincreased and a high saving in initial cost is obtained.

Moreover in my pump the friction between the moving parts is reduced,the peak pressures ironed out and vibration of the parts reduced so thata pump better balanced than known pumps results.

It can thus be appreciated that I have constructed a multi-compartmentrotary pump which greatly improves on the forms of such pumps now in useand which is much simpler and can be made at a materially reduced cost.

I claim as my invention:

In a rotary pump including a shaft and having a pressure side and asuction side, a casing for the pump including an axially extendingportion having a relatively large packing bore and a relatively smallbore providing a bearing for the pump shaft disposed therein, saidcasing'having a passageway leading from the end of the packing bore tothe suction side of the pump, said casing having an internal shoulder atone end of the packing bore, a packing in the packing bore, a metal ringdisposed between the packing and said shoulder and having an annularrecess disposed toward said shoulder and providing a socket affordingcommunication between the surface of the pump shaft and the eway wherebyfluid discharge through the bearing along the shaft will be withdrawnthrough the passageway by a vacuum to the suction side of the pump.

MARK E. ZILIMERER.

